Huawei quidway s7700 Configuration Manual page 266

Quidway S7700 Smart Routing Switch
Configuration Guide - VPN
After the configuration, run the display ip routing-table vpn-instance command on the PEs,
and you can see that the routes to the peer CEs are OSPF routes through the backbone network,
not the BGP routes through the user network.
Take PE1 for example.
[PE1] display ip routing-table vpn-instance vpn1
Route Flags: R - relay, D - download to fib
------------------------------------------------------------------------------
Routing Tables: vpn1
Destination/Mask
255.255.255.255/32
Step 4 Configure a sham link.
# Configure CE1.
[CE1] interface vlanif 20
[CE1-Vlanif20] ospf cost 10
# Configure CE2.
[CE2] interface vlanif 30
[CE2-Vlanif30] ospf cost 10
# Configure PE1.
[PE1] interface loopback 10
[PE1-LoopBack10] ip binding vpn-instance vpn1
[PE1-LoopBack10] ip address 5.5.5.5 32
[PE1-LoopBack10] quit
[PE1] ospf 100
[PE1-ospf-100] area 0
[PE1-ospf-100-area-0.0.0.0] sham-link 5.5.5.5 6.6.6.6 cost 1
[PE1-ospf-100-area-0.0.0.0] quit
[PE1-ospf-100] quit
# Configure PE2.
[PE2] interface loopback 10
[PE2-LoopBack10] ip binding vpn-instance vpn1
[PE2-LoopBack10] ip address 6.6.6.6 32
[PE2-LoopBack10] quit
[PE2] ospf 100
[PE2-ospf-100] area 0
[PE2-ospf-100-area-0.0.0.0] sham-link 6.6.6.6 5.5.5.5 cost 1
[PE2-ospf-100-area-0.0.0.0] quit
[PE2-ospf-100] quit
Step 5 Verify the configuration.
After the configuration, run the display ip routing-table vpn-instance command on the PEs.
You can see that the routes to the peer CEs are BGP routes through the backbone network, and
there are routes to the destination of the sham link.
Take PE1 for example.
Issue 01 (2011-07-15)
Destinations : 6
Proto
20.1.1.0/24 OSPF
30.1.1.0/24 OSPF
100.1.1.0/24 Direct 0
100.1.1.2/32 Direct 0
120.1.1.0/24 OSPF
Direct 0
NOTE
To forward VPN traffic through the MPLS backbone, you must configure the cost of the sham link to be
smaller than the cost of the OSPF route through the user network. A commonly used method is to set the
cost of the forwarding interface on the user network to be greater than the cost of the sham link.
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Routes : 6
Pre Cost Flags
10 2
10 3
0
0
10 4
0
3 BGP MPLS IP VPN Configuration
NextHop Interface
D 100.1.1.1 Vlanif50
D 100.1.1.1 Vlanif50
D 100.1.1.2 Vlanif50
D 127.0.0.1 InLoopBack0
D 100.1.1.1 Vlanif50
D 127.0.0.1 InLoopBack0
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